The invention relates to bicycles, meaning with the term xe2x80x9cbicyclexe2x80x9d any apparatus, mobile or fixed, provided with a pedal group operated by the user of the bicycle, as, for instance, bicycles for touring and for racing, tandem, exercise bikes (cyclette), tricycles.
More particularly, the invention relates to bicycles of the above kind provided with an innovative pedal group able to assure high biomechanical efficiency of the user""s action, to promote the generation of high power during the operation of the pedal group, to allow the user to assume a posture anatomically favourable for the operation of the pedal group, to warrant a very good balancing of the user""s weight and to assure a considerable stability to (mobile) bicycle during motion.
Moreover, the invention relates to bicycles of the above kind provided with an innovative seat able to allow the user to assume a comfortable posture.
Common bicycles presently on the market provide that the pedal group comprises a central shaft, two cranks coupled with the shaft, a pedal coupled with the end of each one of the two cranks and a gear wheel, integrally coupled with the cranks, for transmitting to a chain the motion of the cranks generated by the user through the action of the feet on the pedals. The seat on which the user is sitting during operation of the pedal group is placed at the back of, but substantially in proximity to, the perpendicular to the ground going through the shaft of the pedal group. In the case of mobile bicycles, there are (at least) one front wheel and (at least) one rear wheel having a central hub provided with a freewheeling sprocket to which the chain motion is transmitted in only one way. In the case of fixed bicycles, as cyclette, instead of the wheels, there is (at least) one flywheel, preferably at the back, which offers resistance to the user""s action and to which motion is transmitted similarly to the transmission in mobile bicycles.
As it is known by those skilled in the art, the typology and the position of the pedal group and of the seat of the present bicycles force the user to operate the pedal group assuming a substantially sitting or forward bent position that involves some drawbacks.
First of all, the muscular work of the user""s lower limbs has a non optimal biomechanical efficiency. In fact, this is heavily lowered by the counter-gravity work carried out by the limbs during the pedalling passive phase, by the incomplete extension of the hips, due to the forward position of the pedal group compared to the seat, and by the very low participation of the muscles of the legs, but the quadriceps, in the pedalling active phase.
Moreover, the sitting or forward bent position assumed by the user involves an increased abdominal pressure, known as Valsalva""s phenomenon, due to the reduction of the abdominal cavity, which causes a reduced venous and lymphatic drainage, a reduced pulmonary excursion resulting from the lifting of the diaphragm and a constant stress even of the musculature of user""s bust and arms which gives rise to a rapid fatigue, emphasised in mobile bicycles by the presence of even small unevenness of the run ground.
It is the object of this invention, therefore, to furnish a bicycle allowing the biomechanical efficiency of the user""s action to be optimised.
It is also object of this invention to furnish a bicycle enabling the generation of a high muscular power during the operation of the pedal group in the pedalling active phase.
It is another object of this invention to improve the balancing of the bicyclist""s weight.
It is also object of this invention to furnish a (mobile) bicycle having high stability.
It is further object of this invention to allow the user of the bicycle a comfortable and anatomically favourable for the operation of the pedal group.
It is therefore specific object of the present invention a bicycle and like, having a rear wheel or flywheel, and provided with a pedal group comprising a central shaft and a gear wheel integrally coupled each other, a left crank and a right crank, coupled on the two ends of the central shaft, characterised in that a pedal crank is rotatably coupled with each one of said left and right cranks by mechanical means creating a freewheel like mechanism between the crank and the corresponding pedal crank, a pedal being coupled with one end of each one of the two pedal cranks.
Always according to the invention, said rotating coupling mechanical means between the crank and the corresponding pedal crank can comprise a shaped pin, provided with a ring gear and rotatably coupled with the crank or with the pedal crank, said pin coupling with a corresponding shaped hole provided in the crank or in the pedal crank.
It is further therefore specific object of the present invention a bicycle and like, having a rear wheel or flywheel, and provided with a pedal group comprising a central shaft and a gear wheel integrally coupled each other, a left crank and a right crank, characterised in that said left crank and right crank are rotatably coupled with the central shaft by mechanical means creating a freewheel like mechanism between each crank and the central shaft, a pedal being coupled with one end of each one of the two cranks.
Still according to the invention, said rotating coupling mechanical means between each one of the cranks and the central shaft can comprise a gear coupled with the crank, or to the end of the central shaft, and provided with a shaped hole within which the corresponding end of the central shaft, or a corresponding crank pin, is inserted.
Preferably, according to the invention, in a bicycle having one of the above pedal groups, the central shaft of the pedal group, which is placed parallel with respect to rear wheel hub, is provided externally, above, with respect to the circumference of said rear wheel, within an angle between xc2x130xc2x0 with respect to the line passing through the contact point between the wheel and the ground and the hub.
Furthermore according to the invention, the rear wheel or flywheel hub can be coupled with the central shaft of the pedal group by at least a rod.
Always according to the invention, the bicycle can provide at least a further rod connecting the central shaft of the pedal group with the seat supporting rod, said at least a further rod being included within an angle between xc2x140xc2x0 with respect to a line parallel to the ground and passing through the central shaft of the pedal group.
Still according to the invention, the bicycle can provide at least a further rod connecting the rear wheel or flywheel hub with the lower end of the seat supporting rod, the angle between said at least a further rod and the line perpendicular to the ground and passing through the rear wheel or flywheel hub being between 60 and 120xc2x0.
It is further specific object of the present invention a fixed bicycle, provided with a pedal group operating a rear wheel or flywheel, characterised in that it comprises two tanks, suitable to contain liquid, within each of them a pedal of the pedal group being submerged, within each of the two tanks a cylinder provided with shaped blades and protected by a protection grid being provided, the two cylinders being integrally coupled each other by a shaft inserted within two sealed through holes provided on the faced walls of the two tanks, the shaft centrally providing a bigger diameter disc contacting the rear wheel or flywheel.
Preferably, according to the invention, each one of the two tanks provides a liquid return chute.
It is further specific object of the present invention a bicycle or like, provided with at least one seat coupled with a supporting rod, characterised in that said at least one seat is a swinging seat having a foot pivoted on the head of the supporting rod, the foot being shaped in such a way to provide two surfaces interacting with two mating surfaces of a head projection to limit the rotation with respect to the supporting rod head, elastic means being connected with the seat and the supporting rod.
Always according to the invention, said at least one swinging seat can also comprise a front bodice to support the user bust, said bodice being provided with elastically swinging means.
Still according to the invention, the front bodice can provide a rod, pivoted on the head of the supporting rod and/or on the foot of the seat by said elastically swinging means.
Furthermore, according to the invention, said elastically swinging means can be provided with adjustable friction means able to vary the elastic resistance of the supporting rod opposed by the front bodice to the weight of the supported bust.
Always according to the invention, said at least one swinging seat can provide sliding means to adjust the seat along the longitudinal direction of the bicycle and/or telescopic means to adjust the height and the longitudinal inclination of the seat and/or articulation means to adjust the transverse inclination of the seat.
Still according to the invention, said at least one swinging seat can provide a rear equaliser to support the user bust, said equaliser being provided with elastically swinging means.
Furthermore, according to the invention, the rear equaliser can be connected with the seat and/or with the supporting rod by elastically swinging means.
Preferably, according to the invention, said elastically swinging means provide quick release means.
Always according to the invention, said elastically swinging means can provide adjustable friction means capable to vary the elastic resistance opposed by the equaliser to the user bust.